There are numerous closures for bag-type containers such as polymeric bags that are used for storing non-food items, food products, medical supplies, waste materials, and many other items.
Bag-type containers having closure structures are well known. Typically bag-type containers are provided with mouths or openings along a top side thereof. The mouths or openings are defined by opposed side edges of the containers that can be coupled together along the top side (the closed position) or uncoupled so as to define the mouth or opening (the open position). To provide such a closable function, the opposite side edges of the containers are provided with cooperating structural features that can be coupled together or interlocked.
There are different types of closure structures for bag-type containers, including those that include slider devices that couple and uncouple the closure structures, those that are do not include slider devices that couple and uncouple the closure structures, and those that are resealable and those that are not resealable.
U.S. Pat. No. 5,138,750 to Gundlach et al. exemplifies a bag-type closure that includes a closure structure that is operated by pressing the opposite sides of the mouth of the bag together. Using this type of bag-type closure, the user typically squeezes the opposite sides of the mouth together between his or her thumb and index finger and slides his or her finger and thumb along the mouth of the bag so that the cooperating interlocking or coupling structures are engaged together. An alternative approach that some people take is to squeeze incremental portions of the opposite sides of the mouth of the bag together along the length there. Once closed, the mouth of the bag can be opened by gripping and pulling the opposite sides of the mouth of the bag apart. Such a bag is resealable.
U.S. Pat. No. 2,810,944 to Sander exemplifies a bag-type closure that includes a closure mechanism having a slider. The slider can be thought of as providing a function similar the user's thumb and index finger as discussed above in U.S. Pat. No. 5,138,750. That is, the slider, which is slidably coupled to each of the opposite sides of the mouth of the bag, is configured so that as it is slid in one direction, it couples the cooperating interlocking or coupling structures of the mouth of the bag together. In contrast, as the slider is slid in the opposite direction, it uncouples the cooperating interlocking or coupling structures of the mouth of the bag.
U.S. Pat. No. 5,372,428 to Bruno et al. and U.S. Pat. No. 6,004,032 to Kapperman et al. exemplify non-resealable bag-type closures which are configured to be permanently sealed after various items and substances are placed therein. The mouths of non-resealable bag-type closures include cooperating interlocking or coupling structures, which when engaged together, resist being opened. In some cases, it is known to provide bags having non-resealable bag-type closures with secondary means for gaining access to the contents thereof. For example such bags can include tearable, e.g. perforated, frangible, etc. portions that can be torn apart to gain access to the contents of the bags.
The present invention provides one-way zip-locking closures for bag-type containers.